Comparison of streamflow patterns in drainages of two major terminal basins: the United States Great Basin and Mongolia’s Central Asian Internal Drainage

Abstract

ABSTRACT Current understanding of how streamflow in terminal basins is driven by climatic and hydrogeomorphic characteristics is limited, despite the fact that these closed systems show an increased sensitivity to climate change in terms of streamflow and an increase in demand for water resources. We examined streamflow patterns in 2 major terminal basins, the Great Basin in the United States (US-TB) and the Central Asian Internal Drainage in Mongolia (MN-TB). We obtained daily flow data spanning 1990 to 2014 for both basins, established hydrological indices (HIs), and selected a subset of HIs that best described streamflow patterns. A between-class analysis was used to detect differences in streamflow patterns between these basins. We employed the RESonate tool to delineate hydrogeomorphic patches (HPs), evaluated streamflow variation across distinct HPs, and examined ranges of streamflow variation and hydrogeomorphic variation expressed in each of the terminal basins. Of a subset of 45 HIs, seasonal high flow, flooding frequency, and baseflow best characterized streamflow in HPs. Streamflow in MN-TB was driven by high flow duration, whereas in US-TB streamflow was characterized by significantly larger low-flow conditions. The MN-TB exhibited a greater range of streamflow variation between HPs but showed a lesser range of variation in hydrogeomorphology. Our study is the first to establish HIs and describe streamflow patterns in terminal basins on a large scale. Our study also contributes needed perspectives on streamflow patterns in 2 different terminal basins with complex topographies, thereby providing valuable information for stream ecologists and water resource managers.